For about 40 years, halogenated hydrocarbons (Halon) have been used for extinguishing fires on board aircraft. Halon is partly or completely halogenated hydrocarbons, which engage chemically in the chain reaction of the fire and thus lead to an interruption of the reaction.
Admittedly, the Halon 1211 (chlorine-bromine-difluoro-methane for hand-held fire extinguishes) and 1301 (bromine-trifluoro-methane for installed extinguishing assemblies) contribute to the formation of the stratospheric ozone and therefore are included with the materials which were forbidden in the Montreal Protocol of the United Nations.